They are filled by the emergency (supply) line from the tractor. All material on this website is copyrighted. To do this without wheels chocks you should: Supply air to the trailer air system with the tractor and then disconnect the emergency line. B. open; latched Time limit varies by state. To help avoid mistakes, colors are sometimes used. You are driving a tractor with multiple trailers. Hit the article to see the way to back up your trailer like a pro! Any vehicle, regardless of size, designed to transport 16 or more persons, including the driver. The driver will be required to complete this requirement in three eight hour shifts. We are an independent company focused on providing valuable motor vehicle and permit practice test information. Doubles and triples must be driven very smoothly to avoid rollover or jackknife. If you do cross the air lines, supply air will be sent to the service line instead of going to charge the trailer air tanks. A dolly has lights, air tanks, air relays, air lines, air brakes, ABS, electrical connections, etc. With the red knob pushed in on the tractor dash, the service line should have air in it. The service brakes slowly move to the fully applied position Locking jaws closed on kingpin. Which of the following will probably happen if you are driving a double rig and a set of trailer wheels goes into a skid? Check them all. 0000001956 00000 n some large trucks have curved (convex or spot) mirrors. C. open, except the one connected to the rear trailer should be closed, During normal operation the brakes on double and triple trailers are controlled by the: C. use a light touch on the accelerator and brake pedals, For coupled double and triple trailers, all of the converter dolly shut-off valves should be: Doubles Triples Endorsement Test Flashcards | Quizlet There is no obligation whatsoever. The tanks will hold enough air to allow the brakes to be used several times even if the compressor stops working. c. iron All trademarks are property of their respective owners. The dolly tow bar may fly away, possibly causing panic, and making it very difficult Allow more following distance. be coupled to the rear of a tractor-trailer combination forming a hexagon bottom rig, A coupling device of one or two axles and a fifth wheel by which a semitrailer can be D The number of correct answers. A-dolly. Release Dolly breaks by opening the air tank petcock or if the dolly has a spring break, use the Dolly parking brake control . air throughout the system. The pressure in the service line tells how much pressure the relay valves should send to the trailer brakes. Describe what the trailer air supply control does. C. may have poor traction due to bouncing and wheel lockup, Before you can supply air to the air tanks of a second trailer you need to: Make sure pintle hook is latched. the trailer height is right when: the trailer will be raised slightly when the converter dolly is backed under it. A 360 degree area of awareness is 0000004689 00000 n P0420 code honda odyssey 2011 - pjigzp.wikifit.it You may not notice a major leak in the service line until you try to put the brakes on. For all brakes to work on a triple combination, you must have air supply? 0000004668 00000 n B. the emergency line valve open and release air Make a sketch that explains this phenomenon in terms of a feedback loop . allow "much more space than is needed for ideal driving conditions". D D 1/2 to 3/4 of an inch Florida CDL Handbook | FL CDL Handbook Coupling & Uncoupling for Before you can supply air to the air tanks of a second trailer you need to. A. completely open To help, some companies offer their drivers per diem to get them started Read More, Driving a semi-truck for a living is unlike any other profession. _______ should be tested with the hand valve but controlled in normal operation with the foot pedal. When uncoupling, you should never unlock the _______ with the dolly still under the rear trailer. Flashcards - Doubles Tripes Test #4 - FreezingBlue To check air flows to all trailers, you should let air pressure reach normal then? C What do you check when making a visual check of coupling? The converter dolly air tank drain valve on coupled double/triple trailers should be: You are driving a 100-feet truck with double trailers at 50 mph. Which of the following is true about loading cargo into double or triple trailers? In this order, the shutoff valves at the rear of front trailers, the rear of the last trailer and the converter dolly air tank drain valve should be? There are more critical parts to check when you have two or three trailers. Take special care when pulling two and three trailers. Should the shut-off valves on the rear of the last trailer be open or closed? If you're pulling more than one trailer, all valves should be open except the very last trailer, which should have all valves in the closed position. 1/3 For example: If you are traveling 60 MPH and it begins to rain, your suggested B. you need about four times as much stopping distance at 40 mph as at 20 mph Which of these is most likely to occur? Any trailer with a reduced ground clearance What types of trailers can get stuck on raised crossings? Open, latched 0000003998 00000 n 10 C Dont hesitate to take advantage of our practice tests in each category specific to your needs. To check if the converter dolly is securely coupled to the rear trailer you should: Pull gently against the pin of the second trailer. When you do this, you should hear: If this activity does not load, try refreshing your browser. A Air escape from the open valve B The service brakes slowly move to the fully applied position C The emergency line valve open and release air D None of the above 4. Any combination of vehicles with a gross combined weight rating (GCWR) of 26,001 or more pounds, providing the gross vehicle weight rating (GVWR) of the vehicle being towed is in excess of 10,000 pounds. The best way to keep brakes from getting to hot while going down long grades is to: Go slow and use only light, steady pressure on the brakes. Disconnect the glad-hand at the front of the first trailer and listen for air flow. The emergency line valve open and release air High Road 2.0! Ensuring the safety of the public starts with a thorough inspection of all equipment. You should hear air escaping, showing the entire system is charged. A vehicle transporting hazardous materials is required to display placards where? Converter dollies are connected to front trailers with a? you are visually checking the coupling of a converter dolly to the rear trailer. Why is there still destructive interference? Should the shut-off valves on the trailers be open or closed on a set of double trailers? The puzzle: At the far left edge, the plates are in contact, so the path length difference between rays 222 and 333 is zero. 2. A. for coupled doubles and triples, be sure that the pintle hook is in the open position If spare tire is on converter gear (dolly), make sure it is secured. When you are pulling trailers, which of the following statements is true about steering? Never pull any trailer without visually inspecting the fifth wheel locking bar B When inspecting doubles and triples you must make sure there is air all the way to the back of the last trailer, otherwise what may not work? When the road is dry The Verge logo. The weight of the individual trailers will have no noticeable effect on the handling of the vehicle, The weight of all trailers should be nearly the same, within 2% of each other. Which of these statements about managing space to the sides is true? 9. The pintle hook should always be secure when the vehicle is in motion. Wait for air pressure to reach normal, then push in the red trailer air supply knob. Time allowed (Requires timer add on). Which diagram shows the best way to turn? On the first trailer in a set of doubles? The converter dolly air tank drain valve on coupled double and triple trailers should be: Closed. When checking your air lines, they must be secure and? Newer trailers have spring brakes just like trucks and truck tractors. When connecting a converter dolly to a rear trailer, the trailer height must be adjusted so that it is? The road is dry and the visibility is good. How can you test that air flows to all trailers? The total number of questions. Closed, latched While inspecting your converter dolly coupling, you should make sure there is _____ between the upper and lower fifth wheel. You should hear air escaping, showing the entire system is charged. Should the converter dolly air-tank drain valve be open or closed on a double trailer combination? A You should be sure the converter dolly air tank drain . 7. Refers to pulling two trailers at the same time, otherwise known as "pups" or "pup trailers" because they're only about 28 feet long. With the hand valve on, you should test the trailer brakes by opening the service line valve at the rear of the rig. You are visually checking the coupling of a converter dolly to the rear trailer. Any single vehicle with a GVWR of 26,001 or more pounds, or any such vehicle towing another not in excess of 10,000 pounds. Never, 9. The Doubles and Triples written CDL Exam is required for your doubles and triples endorsement. Do converter dollies have spring brakes? second trailer will be connected, The dolly will have a yellow lamp on the left side, The dolly will have a yellow lamp on the right side, The dolly will have a red lamp on the left side, The dolly will have a red lamp on the right side. You should be sure the converter dolly air tank drain valves are _____ and the pintle hook is _____. 0000002636 00000 n Some areas of concern are discussed below. B 4. Pickup at South Loop. The rear trailer does not have shut-off valves. Air escape from the open valve Some vehicles have dead end or dummy couplers to which the hoses may be attached when they are not in use. Flashcards - Doubles Triples Test #3 - FreezingBlue 0000006383 00000 n 21 0 obj << /Linearized 1 /O 23 /H [ 1162 213 ] /L 29759 /E 11109 /N 7 /T 29221 >> endobj xref 21 38 0000000016 00000 n The emergency brakes come on whenever the air supply knob is pulled out or the trailer is disconnected. If you crossed the air lines, you could drive away, but you would not have trailer brakes. If you do, the brakes may not work correctly. Shut-off valves (also called "cut-out cocks") are used in the service and supply air lines at the back of trailers used to tow other trailers. Seriously! Park the rear trailer against another trailer, chock the tires and lock the trailer This means. 0000001582 00000 n 0000001775 00000 n when testing the coupling of a double trailer the landing gears of the rear trailer should be, you must drive through deep or flowing water . Ship to Store. Have little braking power because they are small Doubles and triples are more likely to turn over than other combination vehicles because of the "crack-the-whip" effect. B A safe speed on a curve for a straight truck or a single trailer combination vehicle may be too fast for a set of doubles or triples. You will speak with recruiters today. 8. If spare tire is carried on converter gear (dolly), make sure it's secured. Number of wrong answers. Free CDL - Doubles and Triples Flashcards | Quizlet True! [Flashing Signals, Traffic Signals, Chapter 5 - Signals, Signs and Pavement Markings, North Carolina Driver's Handbook], One component of the DUI sentence in the state of Tennessee is twenty-four hours of litter pick-up wearing clothing that says "I am a drunk driver." When inspecting a converter dolly What should you check for? Never unlock the pintle hook with the dolly still under the rear trailer. You can find it here: High Road 2.0. B. do not need to be checked as often as flat mirrors because they show a larger area King pin. Pull gently against the pin of the second trailer. Leave the emergency line shut-off valve closed and open the service line valve. If there are no dummy couplers, the glad hands can sometimes be locked together (depending on the couplings). B. allow one vehicle length for every 10,000 lbs of gross vehicle weight All ABS equipped units DMV Doubles Triples Practice Test | CDL Knowledge Doubles and triples are more likely to overturn than other combination vehicles because of the whip cracking effect. Which of the following statements about off tracking is true? A. use a low gear Calculate the net energy change in kilojoules per mole that takes place on formation of MgF2_22(s) from the elements: Heat of sublimation for Mg(s) = 147.7 kJ/mol Eea_{ea}ea for F(g) = -328 kJ>mol, Bond dissociation energy for F2_22(g) = 158 kJ>mol Ei1_{i1}i1 for Mg(g) = 737.7 kJ>mol, Electrostatic interactions in MgF2_22(s) = -2957 kJ/mol Ei2_{i2}i2 for Mg(g) = 1450.7 kJ/mol. Learn more and apply here: TruckingTruth was founded by Brett Aquila (that's me! B. keep other traffic out of your side space A Follow the procedures described later in this section. Some do. Some large trucks have curved (convex or spot) mirrors. Double and triple trailers increase not only the operators risk of safety, but also the other motorists around him. C. if you have traffic on both sides of your vehicle and something is blocking your lane, a move to the right may still be best, To uncouple the rear trailer in a set of doubles, the shut-off valve at the rear of the front trailer should be: Which of these are the correct positions for shut-off valves in doubles and triples? which of these figures shows how the turn should be made, if you want to couple a second trailer to your combination vehicle, secure it by, the trailers spring brakes & wheel chocks. Doubles/Triples Air Brake Check - digital.ncdcr.gov coupled to the rear of a tractor-trailer combination forming a double bottom rig, Careful of the wording! B 0000006836 00000 n Definition. The shortest trailer C You should reduce your speed by about _____ on a wet road. Closed, free, 8. 0000008166 00000 n Use only the trailer brakes They provide the air pressure used to operate trailer brakes. Antilock Braking Systems on Converter Dollies, Converter dollies built on or after March 1, 1998, are required to have antilock brakes. you are driving a 100ft truck eith double trailers at 50mph. Double/Triple Flashcards | Quizlet C. slow to a safe speed before entering the curve, then coast through it, Which of these is NOT a good thing to do when driving on slippery roads? The application only takes one minute. the best way to keep brakes from getting too hot while going down long grades is to : go slow and use only light, steady pressure on the brakes, you are driving a 100ft truck with double trailers at 30mph. Email Updates When New Articles Are Posted. Open Any trailer, 7. Amazon.com: Air Tank Drain Valve Chock the tires, park on level ground and charge the trailer air tank if it does A Which is most likely to tip over: door. When you uncouple twin trailers, the last step is to Converter dollies You want to hook your combination to a second trailer that has no spring brakes. Before you can supply air to the air tanks of a second trailer you need to: Open the shut-off valves at the rear of the first trailer and close the shut-off valves at the rear of second trailer. A driver of a vehicle with double or triple trailers will have greater length and more dead axles to pull, increasing the likelihood of a wreck. Make sure to visually inspect the fifth wheel and that the locking mechanism is When coupling, be sure to couple the proper glad hands together. Speed for other vehicles is often too fast for a multi-combination unit! Therefore, it is very important for safety that you use wheel chocks when you park trailers without spring brakes. B Hook dolly to front trailer. Pintle-eye of dolly in place in pintle hook of trailer (s). Hit the article below to see specific information about AOBRDs! You should be sure the converter dolly air tank drain valves are _____ and the pintle hook is ____. To check that the trailer emergency brakes are working properly, you should pull out the trailer air supply control and? The rear trailers shut off valves should be closed and the front open to allow air to the Always test the trailer brakes before driving with the hand valve or by pulling the air supply (tractor protection valve) control. . converting it into two trailers, A coupling device of three or four axles and a fifth wheel by which a semitrailer can CDL: Doubles/Triples Flashcards | Quizlet Doubles and triples are more likely to turn over than other combination vehicles because of what effect? CDL License Requirements State By State.